279 research outputs found

    Polarization and angular distribution of the radiation emitted in laser-assisted recombination

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    The effect of an intense external linear polarized radiation field on the angular distributions and polarization states of the photons emitted during the radiative recombination is investigated. It is predicted, on symmetry grounds, and corroborated by numerical calculations of approximate recombination rates, that emission of elliptically polarized photons occurs when the momentum of the electron beam is not aligned to the direction of the oscillating field. Moreover, strong modifications to the angular distributions of the emitted photons are induced by the external radiation field.Comment: 5 pages, 3 figure

    Two-color ionization of hydrogen by short intense pulses

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    Photoelectron energy spectra resulting by the interaction of hydrogen with two short pulses having carrier frequencies, respectively, in the range of the infrared and XUV regions have been calculated. The effects of the pulse duration and timing of the X-ray pulse on the photoelectron energy spectra are discussed. Analysis of the spectra obtained for very long pulses show that certain features may be explained in terms of quantum interferences in the time domain. It is found that, depending on the duration of the X-ray pulse, ripples in the energy spectra separated by the infrared photon energy may appear. Moreover, the temporal shape of the low frequency radiation field may be inferred by the breadth of the photoelectron energy spectra.Comment: 12 pages, 8 figure

    Efficacy of a functional therapy program for depression and c-reactive protein: A pilot study

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    Objective: Affecting more than 264 million people, depression is a systemic and multifactorial disorder that represents one of the leading causes of illness and disability worldwide. Several studies showed an inflammatory response in depressed patients, including the involvement of both chronic low-grade inflammatory response and activation of cell-mediated immunity. The present study aimed to verify the efficacy of a structured functional therapy program for patients with depressed mood, and to determine whether this program can significantly reduce levels of C-reactive protein. Method: 28 outpatients with depressed mood received 20 individual sessions of Functional therapy. Data about socio-demographic variables, depression, self-esteem, and quality of life were collected; moreover, blood specimens were collected before and after treatment, and CRP measurement was performed by immunoenzymatic method. All measures were administered at baseline, at the end of treatment (i.e., 3 months after baseline), and at follow‐up (i.e., 6 months after baseline). Results: A repeated measures ANOVA showed a significant difference after treatment on depression levels, levels of self‐esteem, and all dimensions of quality of life, such as physical, psychological, social relationships, and environment. Furthermore, a statistically significant difference on levels of CRP was found. Moreover, at follow‐up, improvements were maintained. Conclusions: The study revealed initial evidence of the efficacy of a functional therapy program on treating depression and its psychological and inflammation-related markers

    Aurora kinase A drives the evolution of resistance to third-generation EGFR inhibitors in lung cancer.

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    Although targeted therapies often elicit profound initial patient responses, these effects are transient due to residual disease leading to acquired resistance. How tumors transition between drug responsiveness, tolerance and resistance, especially in the absence of preexisting subclones, remains unclear. In epidermal growth factor receptor (EGFR)-mutant lung adenocarcinoma cells, we demonstrate that residual disease and acquired resistance in response to EGFR inhibitors requires Aurora kinase A (AURKA) activity. Nongenetic resistance through the activation of AURKA by its coactivator TPX2 emerges in response to chronic EGFR inhibition where it mitigates drug-induced apoptosis. Aurora kinase inhibitors suppress this adaptive survival program, increasing the magnitude and duration of EGFR inhibitor response in preclinical models. Treatment-induced activation of AURKA is associated with resistance to EGFR inhibitors in vitro, in vivo and in most individuals with EGFR-mutant lung adenocarcinoma. These findings delineate a molecular path whereby drug resistance emerges from drug-tolerant cells and unveils a synthetic lethal strategy for enhancing responses to EGFR inhibitors by suppressing AURKA-driven residual disease and acquired resistance

    A 24 hour naproxen dose on gastrointestinal distress and performance during cycling in the heat

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    Using a double-blind, randomized and counterbalanced, cross-over design, we assessed naproxen's effects on gastrointestinal (GI) distress and performance in eleven volunteers (6 male, 5 female). Participants completed 4 trials: 1) placebo and ambient); 2) placebo and heat; 3) naproxen and ambient; and 4) naproxen and heat. Independent variables were one placebo or 220 mg naproxen pill every 8 h (h) for 24 h and ambient (22.7 ± 1.8°C) or thermal environment (35.7 ± 1.3°C). Participants cycled 80 min at a steady heart rate then 10 min for maximum distance. Perceived exertion was measured throughout cycling. Gastrointestinal distress was assessed pre-, during, post-, 3 h post-, and 24 h post-cycling using a GI index for upper, lower, and systemic symptoms. No statistically significant differences occurred between conditions at any time for GI symptoms or perceived exertion, distance, or heart rate during maximum effort. A 24 h naproxen dose did not significantly affect performance or cause more frequent or serious GI distress when participants were euhydrated and cycling at moderate intensity in a thermal environment

    H-Ras Nanocluster Stability Regulates the Magnitude of MAPK Signal Output

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    H-Ras is a binary switch that is activated by multiple co-factors and triggers several key cellular pathways one of which is MAPK. The specificity and magnitude of downstream activation is achieved by the spatio-temporal organization of the active H-Ras in the plasma membrane. Upon activation, the GTP bound H-Ras binds to Galectin-1 (Gal-1) and becomes transiently immobilized in short-lived nanoclusters on the plasma membrane from which the signal is propagated to Raf. In the current study we show that stabilizing the H-Ras-Gal-1 interaction, using bimolecular fluorescence complementation (BiFC), leads to prolonged immobilization of H-Ras.GTP in the plasma membrane which was measured by fluorescence recovery after photobleaching (FRAP), and increased signal out-put to the MAPK module. EM measurements of Raf recruitment to the H-Ras.GTP nanoclusters demonstrated that the enhanced signaling observed in the BiFC stabilized H-Ras.GTP nanocluster was attributed to increased H-Ras immobilization rather than to an increase in Raf recruitment. Taken together these data demonstrate that the magnitude of the signal output from a GTP-bound H-Ras nanocluster is proportional to its stability
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